Check the company’s W-2, W-9, 1099, or other tax forms
Review the company’s annual report, SEC filings, or public financial documents
Search the company’s website, especially investor relations or legal pages
Look up state business registration records
Use the IRS Tax Exempt Organization Search if the company is a nonprofit
Search business directories or databases that list EINs
Contact the company’s payroll, HR, or accounting department
Ask the company directly for its EIN
Check loan, banking, or vendor documents if you have authorized access
Hire a professional service or use a paid EIN lookup database if needed